Method of clinching bail ears to can body blanks and apparatus therefor



Dec. 14, 1948. J. HENCHERT 2,456,506

METHOD OF CLINCHING BAIL-EARS T0 CAN BODY BLANKS AND APPARATUS THEREFOR Filed Dec. 21, 1945 2 Sheets-Sheet l Dec. 14. 1948. J HENCHERT 2,456,506

METHOD OF CLINCHING BAIL-EARS T0 CAN BODY BLANKS AND APPARATUS THEREFOR Filed Dec. 21, 1945 2 Sheets-Sheet 2 l i 14 A l6 5 5 /6 d 23 24 g 24 Z4 Z8 /6 4 75 1 g i 28 z 1 2 Q i I i Q 25 .|I 25 21627 i Z9 Z5 I l u 5 5 Z7 I z 29 4 -i 27 29 E 29 i l v Patented Dec. 14,

METHOD OF CLINCBING BAIL EARS TO CAN gggY BLANKS AND APPARATUS THERE- John Henchert, Chicago, 111., aeaignor to Continental Can Company, Inc., New York, N. Y.,

a corporation of New York Application December 21, 1945; Serial No. 636,428

Claims. (Cl. 113-116) 1 The following is a specification of my invention in a method of clinching bail-ears to can body blanks, apparatus therefor and the article produced.

In the manufacture of sheet metal cans with attached bails such as are frequently used for paints, foods and like material, it is important that the ears by which the balls are connected to the can bodies shall be attached on the outside of the latter so that no seams will be necessary. Various methods of attachment are used. It is, however, a problem to secure the bail-ears satisfactorily to a can which has a curvilinear surface. Thus, for example, a cylindrical can does not oiTer an entirely satisfactory surface upon which to apply the planar flange of the customary bail-ear. If the ear is attached to the can blank when the latter is flat, the subsequent operation of bending the blank into a cylindrical form very frequently results in retaining a flat panel or stave underneath the ear and along the related surface of the body. This has always been recognized as an undesirable but generally expected condition.

If on the contrary the can blank does take a cylindrical curvature beneath the point where the ear has been attached, the attachment may be weakened. If the mode of attachment is by a bead swaged over the flange of the ear, there may be relative separation of the two, which materially weakens the attachment of the ear.

My improved method of attaching bail-ears to can bodies avoids the above difficulties and provides a superior article in which the uniform' curvature of the body is preserved without in any 'way weakening the attachment of the bail-ear.

An object of the invention is to so apply the ears to the body blank that 'when the body blank shaped into body form said body shall be of uniform curvature throughout.

.A further object of the invention is to provide a method of clinching the bail ears onto the body blank which is to be formed into a cylindrical can body, wherein the body blank in the region where the ears are to be attached, is curved to conform substantially to the final curvature of the body either previously'to or simultaneously with the clinching operation.

A still further object of the invention is to design a machine by which the improved clinching method maybe carried out. r

In the drawings which show a machine for clinching ears to a can body blank by the improved method:

a Fig. 1 is a vertical axial section of a machine arranged for clinching bail-ears to can blanks;

Fig. 2 is a perspective view of the bail-ear to be attached;

Fig. 3 is a fragmentary plan view of a can blank on which the bail-ear is to be clinched;

Fig. 4 is a vertical axial section of the machine with the can-blank curved;

Fig. 5 is a similarsection of the machine with the bail-ear clinched to the can blank and Fig. 6 is a vertical axial section of the machine taken on the line 6-6 of Fig. 5.

It is first to be understood that the bail-ears are to be applied to a can body blank which has already been given preliminary treatment.- The sheet from which the blanks are taken has been given a grain breaking operation which puts the blank into appropriate condition for being curved into body form without danger of developing flats or panels due to local stresses in the sheet structure.

As is usual the sheet or blank is oiled over the surfaces which are to be formed by dies.

The next preliminary operation on the body blank consists of providing in the blank a clinching rib generally circular and surrounding the area to be occupied by the bail-ear. I

The bail-ear is also fed into the circular recess formed by the rib, and the flat blank with the bail ear is then advanced into position for clinching the bail-ear to the blank. It will beunderstood that the above preliminary steps can be carried out by.means and methods now known and the details of which are not important to this invention. I

The can body blank I in fiat form and prepared by the previously described treatment has a preformed rib 8 which is circular and large enough to fit around the bail-ear,

The bail-ear 9 is stamped from sheet metal and has a generally conical form. The side wall is peripherally grooved to form the shoulder 3i. By this arrangement the balls can readily be stacked vertically and yet prevented from stick ing together. It has a flat peripheral flange Ill around the hollow base.

A bed die His provided upon which the clinching operation is to be carried out. The die has a cylindrical top surface i2 conforming in curvature to that of the completed can that is to be produced. The die. also has a generally circular rib l3 conforming to the shape and size of the rib 8 in the blank. The rib I3 is of such size that it does not interfere with the progressive feeding of the flatv blank nor its removal after being curved. At the same time it serves I die face I2.

to center the blank in the desired position for the clinching operation.

The ear 9 has previously been set on the blank 1 within the rib 8 and fed to the machine with the blank.

A clinching or swaging die I4 is arranged in a suitable support to slide vertically above the bed die II. This clinching die I4 has an axial bore I5. The lower portion of the bore I5 is enlarged as shown at I6.

A lower face H of the die I4 is appropriately chamfered and has a concentric inner groove I8. The face I! and groove I8 have a transverse cylindrical curvature of the same radius as that of the upper surface I2 of the bed die.

A hold-down plunger I9 is slidably carried within the enlargedbore I6 of the clinching die.

' The plunger has a reduced stem 28 which passes through the axis of the die I4 and projects above as shown in Fig. 1. Lock nuts 2|, 2| are fastened together on the stem 20 above the clinching die I4 and limit the downward movement of the plunger I9.

A helical spring 22 occupies the enlarged bore I6 back of the head of the plunger I9.' Normally this spring holds the plunger in its lower position with the lock nuts 2| resting against the upper end of the clinching die. By adjusting the position of the nuts 2|, 2| it is possible to accommodate bail-ears of different heights.

The die I4 carries two or more circumferentially spaced bosses 23, 23. Each boss has a vertical recess 24 in the bottom of which there is an opening 25.

An outer-annular curving die 26 is slidably mounted upon the outer surface of the clinching die I4. The annular die is tapped to receive screw bolts 21, 21. The heads 28 of the bolts are loosely held in the recesses 24 and rest on the bottoms thereof. Helical springs 29 29 surround the bolts 21 and serve to hold the dies 26 normally in their lower positions spaced from the bosses 23.

The bottom die face 30 has a cylindrical concavity of the same radius of curvature as the Suitable means, not illustrated, are provided to maintain the clinching die I4 and the curving die 26 with their cylindrical concave faces coaxial with the die face l2.

As already stated the blank 1 with the bail-ear tion the circular rib 8 overlies rib I3 on the bed die.

In the first phase of the downward movement of the die I4 and its associated parts, the holddown plunger I9 rests upon the top of the ear 9 and maintains it firmly within the rib B.

As the die I4 continues to move downwardly, spring 22 is compressed allowing the plunger I9 to maintain a relatively fixed position. At the same time the flange Ill of the ear is brought firmly into contact with the blank for its entire circumference.

Continued downward movement of the die I4 brings the curving die 26 into contact with the upper face of the blank I. The blank I is thus bent downwardly by the die 26 and the blank given a curvature conforming to that of the die face I2 to the limited extent indicated in Figs. 4 and 5.

In the course of this movement the portion of the blank 1 within the rib 8 is also bent slight- 1y into a similar curvature. The rib 8 fits over the rib I9 of the die I2 but extends farther upwardly producing an upstanding surplus rib of the blank.

This curving of the blank! gives its inner wall a substantially uniform curvature as shown in Figs. 4 and 5. This curvature, however, is cylindrical and as a result the blank is perfectly straight in the direction at right angles to the curvature. This is indicated in Fig. 6. The final downward'movement of the die I4 compresses the coil spring 29 and the coil spring 22 as much farther as is necessary without altering the position of either the hold-down plunger I9 or the annular die 26. The final limit of movement for the plunger I9 and the die 26 is shown in Fig. 4.

Continued movement of the die I4, independently of the plunger 19 and the annular die 26, brings the face I! of the die I4 down until it rests upon the top surface of the blank. In'the course of this operation the groove I8 performs a clinching, swaging or upsetting operation. This folds down the rib 8 over the flange III all around the ear. There is thus formed a'tight crimped seam uniformly surrounding the flange I0 and slightly distorting it out of its normal plane. Thus as shown in Fig. 5, diametrical points of the flange follow the curvature of the blank and out of the plane of the points of the flange at a right angle therefrom as shown in Fig. 6.

The result of this movement is to clinch the flange of the bail-ear 9 tightly within and uniformly around the folded rib 8.

This is the ultimate curved form of the can. It is therefore not subject to weakening or other alteration in shape during the subsequent manufacturing operation. On upward retraction of the die I4 the swaging face I'I leaves the blank first and is followed successively by the annular die 26 and the hold-down plunger I9. The die is thus separated from the work and the clinched blank may then be removedfrom the bed die I2 mechanically or even manually.

Any mechanism for feeding the blanks, and operating the dies may readily be supplied in conjunction with the operations above described.

The above illustrative description exemplifies the improved method of clinching bail-ears to can blanks. It is also well adapted for affixing the bail ears to cans or pails which have been given curvilinear form. It is also apparent that the mechanism by which the method is carried out is simple, efficient and durable and may be altered in minor details or proportions as occasion and circumstances may suggest. Accordingly the scope of my invention is not dependent upon the specific details described above but is limited solely by the definitions set out in the following claims.

What I claim is:

1. The method of clinching bail ears to can body blanks which comprises forming an upstanding annular rib on said blank. assembling an ear with a peripheral flange within said upstanding rib, shaping the blank around the rib into a cylindrical arc having a uniform continuous curvature, pressing the car down with its flange in partial contact with the curved blank and clinching the rib over the flange, and simultaneously therewith causing the flange of the ear and rib to conform to the curvature of the blank.

2. vThe method of attaching ears to can body blanks which consists in forming the blank with an upstanding annular rib, assembling an ear with a. peripheral flange within the upstanding rib, shaping the blank into a uniform cylindrical arc in the region of the rib, pressing the car down with its flange in contact with the arcuate portion of the blank within the rib, and clinching the formed rib of the body blank over the flange of the ear, and simultaneously therewith forming the flange of the ear and rib to conform to the curvature of the blank.

3. The method of attaching ears to can body blanks which consists in forming the blank with an upstanding annular rib, assembling an ear with a peripheral flange within the upstanding rib, shaping the blank into a uniform cylindrical arc in the region of the rib by means of pressure against a curved faced die, pressing the car down with its flange in contact with the arcuate portion of the blank within the rib, and clinching the formed rib of the body blank over the flange of the ear, and simultaneously therewith by means of pressure against said die forming the flange of the ear and rib to conform to the curvature of the blank.

4. A machine for clinching a bail-ear to a can body blank comprising a cylindrical die having a uniform continuous curvature, means on the die to position a circularly ribbed can body blank, a clinching die reciprocable toward and from said first-named die, means resiliently mounted on the clinching die to hold a bail-ear against the blank and within the rib thereon, and means re- 30 sillently mounted on the clinching die to bend the portion of the blank around the rib down into contact with the cylindrical die in advance of the clinching action of the clinching die.

5. A machine for clinching a bail-ear to a can body blank comprising a fixed cylindrical die, means on the die to position a circularly ribbed can body blank, a clinching die reciprocable toward and from said first-named die, said clinching die having a cylindrical face coincidental with the surface of the fixed die, resilient means for holding the bail-ear down upon the blank, an annular die slidably carried by the clinching die, said annular die having a cylindrical face coincidental with the surface of the fixed die, and resilient means for holding the annular die in its forward position.

JOHN I-IENCHERT.

I file of this patent:

UNITED STATES PATENTS Number Name Date 521,858 Higgins June 26, 1894 758,503 Blevins et al Apr. 26, 1904 1,003,691 Benedict Sept. 19, 1911 1,865,144 Sebell June 28, 1932 1,948,553 Widell Feb. 27, 1934 FOREIGN PATENTS Number Country Date 170,337 Great Britain Oct. 21, 1921 

